SREL Reprint #3827

Habitat-specific seasonal densities of sympatric raccoons and opossums in the southeastern United States

Jacob E. Hill1,6, Madison L. Miller1,7, Richard B. Chipman2, Amy T. Gilbert3, James C. Beasley1,4,
Guha Dharmarajan1,8, and Olin E. Rhodes1,5

1Savannah River Ecology Laboratory, University of Georgia, PO Drawer E, Aiken, SC 29802, United States
2National Rabies Management Program, USDA, APHIS, Wildlife Services, Concord, NH 03301, United States
3National Wildlife Research Center, USDA, APHIS, Wildlife Services, 4101 Laporte Avenue,
Fort Collins, CO 80521, United States
4Warnell School of Forestry and Natural Resources, University of Georgia, 180 E Green Street,
Athens, GA 30602, United States
5Odum School of Ecology, University of Georgia, 140 E Green Street, Athens, GA 30602, United States
6Department of Fisheries and Wildlife, Michigan State University, 480 Wilson Road #13,
East Lansing, MI 48824, United States
7Division of Forestry and Natural Resources, West Virginia University, Morgantown, WV 26505, United States
8Division of Sciences, School of Interwoven Arts and Sciences, Krea University, Sri City, Andhra Pradesh, India

Abstract: Raccoon and opossum densities have implications for rabies management, but estimates of seasonal densities of both species are lacking for rural nonagricultural habitats of the southeastern United States, a core portion of their geographic range. Consequently, it remains unclear whether the densities of 1 species limit the other, which is possible considering their substantial niche overlap. We carried out a mark–recapture study of raccoons and opossums in 4 rural nonagricultural habitats (bottomland hardwood forest, riparian forest, upland pine forest, and isolated wetlands) in South Carolina, United States (2020 to 2022), and combined this with previous data from the same habitats (2017 to 2019) to estimate habitat-specific spring and fall densities. Raccoon densities ranged from 5.17 ± 0.96 animals/km2 (bottomland hardwood fall) to 1.63 ± 0.83 animals/km2 (upland pine spring) and were on average 19% higher in fall compared to spring. Opossum densities ranged from 10.35 ± 1.98 animals/km2 (bottomland hardwood fall) to 1.11 ± 1.55 animals/km2 (upland pine spring) with divergent seasonal patterns among habitats. These low densities across all habitats compared to other studies are likely the result of low resource availability, consistent with other habitats that have minimal anthropogenic influence. We observed a positive association between raccoon and opossum densities across trapping grids, suggesting that raccoons do not suppress opossum densities, but that densities of both species increase with increasing resource availability. Our results can be used to inform oral rabies vaccination efforts such as refining bait densities and timing of bait distribution in these habitats.

Keywords: demography, Didelphis virginiana, human–wildlife conflict, mark–recapture, mesocarnivore, oral rabies vaccination, population density, Procyon lotor

SREL Reprint #3827

Hill, J. E., M. L. Miller, R. B. Chipman, A. T. Gilbert, J. C. Beasley, G. Dharmarajan, and O. E. Rhodes. 2025. Habitat-specific seasonal densities of sympatric raccoons and opossums in the southeastern United States. Journal of Mammalogy 106: 683-691.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).